Two lift kits can read the same on a tape measure and do completely different things to your suspension travel. Here is the difference, and why one of them shows up in the shop as torn CV boots.
The Short Answer
A preload lift raises the truck by compressing the factory spring a little further at rest and letting the spring's own natural rate carry the height. The spring rate does not change. An under-spring collar, a spring spacer on the seat, or a top hat with preload machined into it all work the same way, and all of them leave both shock mounts exactly where the factory put them — so full droop, full compression, CV joint angle, ball joint angle, tie rod angle and brake hose slack are unchanged. A spacer stacked above the shock's upper mount raises the truck by pushing the whole assembly down into the chassis. At full droop the suspension now reaches past the point the factory chose to stop it, and at the wheel it reaches further than the spacer is thick. The one thing a top spacer genuinely does better is tire clearance at full compression. Everything else it changes, it changes for the worse.
There is a long-running argument about how to add front ride height to a factory off-road truck, and it has gotten louder as more owners lift the Ford Ranger Raptor. One side says a spacer above the shock mount is the better approach because the shock keeps its factory position at ride height. The other side says that method buys its height by letting the suspension travel past where it was designed to stop.
We build lift collars, so our position is not a secret. But the argument is worth having properly, because the confusing part is that the name on the box does not tell you which kind of lift you bought — and one of the two categories is a great deal harder on your truck than the other.
The Only Distinction That Matters
Forget the product names for a moment. There are only two ways to add front ride height to a coilover front end, and the difference is where the hardware sits relative to the shock's mounting points.
Preload Lifts
A spring perch collar under the coil, a spring spacer on the seat, a top hat with preload built into it, or a taller-rate replacement spring. All of these simply preload the factory spring further and use its natural rate to gain the height. The spring rate is not altered and the shock's upper and lower mounts never move. The truck rises because the spring is starting from a more compressed position, not because anything was relocated.
This is the part that trips people up: a top hat is not automatically a spacer. Plenty of billet top hats are preload devices that behave exactly like a collar. Ask which one you are buying.
Relocation Lifts
A puck or spacer sandwiched between the shock's upper mount and the chassis. The spring and shock are untouched internally, but the whole assembly now sits lower in the truck by the thickness of that spacer. The truck rises because the control arm has been pushed down.
Both give you inches. Only one of them leaves the suspension's designed travel limits where the engineers put them.
What a Preload Lift Leaves Alone
Because a preload collar does not move either shock mount, a long list of things stays exactly as the factory built it.
1. Full Droop Position
The suspension still stops drooping at the same place it always did, because the shock is still what stops it — a part designed to be a travel stop.
2. Full Compression Position
The bump stop still makes contact at the same point in the stroke. Nothing about the top of the travel has moved.
3. CV Joint Angle and Plunge
The axle never sees an angle or an amount of plunge that the factory did not already design around and validate.
4. Ball Joint and Tie Rod Angles
Both stay inside their designed working range at full droop, so they are not binding against their own limits on every big hit.
5. Brake Hose and Harness Slack
The brake hose and the wheel speed sensor harness are never pulled further than they were built to stretch.
6. Spring Rate and Shock Stroke
The spring keeps its factory rate and the shock keeps its full stroke. What changes is where the truck rests inside that stroke — more up-travel, less down-travel.
That last one is the honest trade, and we will state it plainly: sitting higher means the truck rests further out in the shock's travel, so you gain up-travel and give up some down-travel, and the first part of the stroke feels a little firmer because the spring starts from a more preloaded position. Every part of that happens inside limits the factory already validated.
What Happens to the Electronics
On the Ranger Raptor and other trucks running a Live Valve shock package, this is the first question owners ask, and it has a straightforward answer. After the lift you can re-calibrate the ride height position so the truck knows where it is now sitting. Once it does, the electronic side of the suspension goes back to performing the way it was intended to.
That calibration does not move the mechanical internal bypass positions — those are machined into the shock and they stay exactly where Fox put them. Nothing about the shock's internals changes when you add preload, which is the whole point.
What does change is where the truck rides within those fixed zones. Raise it up and the shock sits in a lighter zone for normal street driving. And because the mechanical zones never moved, you are not giving up bump zone, or travel, or anything else to get there.
What a Top Spacer Changes
Drop the shock assembly two inches into the chassis and the control arm goes with it — not just at ride height, but at every point in the stroke, including the very bottom.
At full droop, the arm now hangs further down than the factory ever allowed it to. On a double-wishbone front end the shock mounts to the lower arm inboard of the ball joint, so the movement at the wheel is larger than the spacer itself. A two-inch puck is more than two inches of extra droop out at the tire.
So What Is Stopping It Now?
The shock still limits at its own internal extension stop, so the assembly runs out of travel in the same place relative to itself. But everything connecting the knuckle to the truck is now being asked to reach further than it was designed to: the CV joint, at more angle and more plunge than the factory envelope. The lower ball joint, past its designed working angle. The outer tie rod end, same problem. The brake hose and wheel speed sensor harness, pulled past their designed slack. The sway bar end links, over-extended.
None of those parts is a travel stop. They are steering and drive components that happen to be in the way. A suspension should be limited by a part built to limit it — a shock, a bump stop, or a limit strap.
What Comes Through the Door
This is not a thought experiment for us. We have had trucks come into the shop running top puck spacers with torn CV boots and damage to the surrounding components. Removing those top spacers was part of the repair — there is no point replacing a boot or a joint and leaving in place the thing that overextended it.
We do not build trucks with top spacers, and we do not recommend them. That is not a gap in our testing, it is the conclusion. There is no reason to build something and run it just to confirm what we have already seen come apart on our own lift. If a method ends with a CV joint acting as the travel stop, we are not going to put our name on it and then go looking for numbers to justify it.
The One Thing a Top Spacer Does Better
A top spacer genuinely buys tire clearance at full compression. Because the whole assembly sits lower in the truck, the tire stops lower in the wheel well when the suspension is fully stuffed. If you are fitting a taller tire and your problem is rubbing at full compression, a spacer addresses that directly. A preload collar does not — the tire still compresses to the same point it always did, because the bump stop contacts in the same place.
So if that is the problem you are actually solving, say so plainly. But there is a way to get clearance without handing your droop limit to a CV joint: control the compression side on purpose. A bump stop and limit strap kit sets both ends of the travel deliberately, with parts designed to be travel stops, and lets you dial clearance for the tire you are actually running. That is the tool for the job. Over-extending the bottom of the suspension is a side effect, not a solution.
An Argument That Only Works on One End
Here is the part of this debate that rarely gets mentioned, and it is the part that gives the game away.
On the Ford Ranger Raptor and the Bronco Raptor, the rear shocks are mounted in a way that does not let you stack a spacer above them the way you can at the front. If you want rear lift on those trucks, you have exactly two options: add preload, or fit a heavier spring. There is no third choice.
Which means everybody lifting the rear of these trucks — including everyone arguing that preload is the wrong approach at the front — is already running a preload lift out back. If preload genuinely ruined ride quality and shock behavior, the rear of these trucks would be unfixable. It is not. It works, it has worked for years, and it works for the same reason it works at the front: the shock stays where it was mounted and the travel limits stay where they were set.
An argument that only holds up on one end of the truck is not an argument about physics. It is an argument about one product.
Preload vs. Relocation, Side by Side
| What matters | Preload lift (collar, spring spacer, preload top hat) |
Relocation lift (puck above the shock mount) |
|---|---|---|
| Shock mounting points | Unchanged | Upper mount moves down |
| Spring rate | Factory | Factory |
| Droop past the factory limit | No | Yes — more than the spacer at the wheel |
| CV, ball joint and tie rod angle at full droop | Factory | Beyond factory |
| What stops the suspension at full droop | The shock, as designed | Whichever part runs out first |
| Brake hose and harness slack | Factory | Reduced |
| Mechanical bypass zones in the shock | Unmoved | Unmoved |
| Tire clearance at full compression | Unchanged | Improved |
| Ride height adjustable later | Yes — swap the collar | Yes — swap the spacer |
| Works on a rear shock that cannot be spaced from above | Yes | No |
Why This Comes Up Most on the Ranger Raptor
The 2024 and newer Ford Ranger Raptor lands in the middle of this debate more than any other platform. It leaves the factory with noticeable rake, so almost everyone wants front height. It runs a Fox Live Valve shock package that owners are reasonably protective of. And it is a global truck, which means lift parts developed for one market get argued about in another.
Our position on the Ranger Raptor is the same as on every other platform we build for: add the height with preload, leave the shock where Ford mounted it, and keep the factory droop limits intact. Re-calibrate the ride height afterward and the Live Valve system does its job exactly as before. If you are running larger tires and fighting contact at full compression, that is a compression-side problem and it wants a compression-side fix — call us rather than solving it by adding droop.
Ranger Raptor Front Lift
2024+ Ford Ranger Raptor. Works with the factory Fox Live Valve shock package.
The Next Chapter: Mid Travel and Long Travel
We should be straight about the ceiling here, because it applies to collars and pucks alike. A lift collar is worth a couple of inches of ride height, and that is all it is worth. It changes stance. It does not make the truck handle better, and it does not give you more usable wheel travel. If your goal is a truck that works harder at speed, a lift kit of any kind is not the part that gets you there.
The way you actually get better, more functional travel is to change what the suspension has to work with. That means a mid travel front suspension kit — bypass shocks, front bump stops, and the arms to go with them. That is a real change in how the front end absorbs terrain, not a change in how the truck looks parked.
On the Ranger Raptor specifically, the next chapter is out back: a rear long travel kit with a coil-over through the bed that adds three-plus inches of wheel travel. When a collar or a spring lift is not enough any more, that is where the conversation goes.
When You Want More Than Stance
2024+ Ford Ranger Raptor rear long travel. For Raptor and Bronco Raptor, start with the mid travel front kits.
Match the Method to the Problem
Lift Collar and Spacer FAQs
What is the difference between a lift collar and a top hat spacer?
It depends entirely on where the hardware sits. A lift collar goes under the spring and adds preload, leaving both shock mounts alone. A top hat can be either — some have preload machined into them and behave exactly like a collar, while others are a puck that stacks above the shock's upper mount and lowers the whole assembly. Ask which one you are buying, because the two do very different things to your droop travel.
Can a leveling spacer damage CV joints?
A spacer above the shock mount lets the suspension droop further than the factory designed for, which puts the CV joint at more angle and more plunge than it was built to see. We have had trucks come in with that style of spacer showing torn CV boots and damage to the surrounding components, and removing the spacers was part of the repair. A preload collar does not change droop at all, so it does not create this problem.
Does a lift collar change the spring rate?
No. The collar preloads the factory spring further and uses the spring's own natural rate to gain the height. The rate is whatever Ford or Ram specified, before and after.
Do lift collars reduce suspension travel?
No. Total shock stroke is exactly the same before and after. What changes is where the truck rests inside that stroke — you gain up-travel from ride height and give up some down-travel. The travel itself is unchanged, and so are both ends of it.
Will a lift kit upset the Live Valve system on a Ranger Raptor?
Not once the ride height position has been re-calibrated. After that the truck knows where it is sitting and the electronic side performs as intended. The mechanical internal bypass zones in the shock do not move at all — raising the truck on preload simply means it rides in a lighter zone for normal street driving, without giving up bump zone or travel to get there.
Is added spring preload bad for the shock?
No. Preload does not change the spring rate, the shock's stroke, or its mounting position. It is the same mechanism used to set ride height on virtually every adjustable coilover ever built, and it is the only way to lift the rear of trucks whose rear shocks cannot be spaced from above.
Why can't I just put a spacer above the rear shock?
On a number of platforms, including the Ranger Raptor and the Bronco Raptor, the rear shock mounting does not allow it. Rear lift on those trucks comes from preload or from a heavier spring — a useful reminder that preload is a normal, accepted way to set ride height rather than a compromise.
Will a top spacer let me run a bigger tire?
At full compression, yes — that is the one place a spacer has a real advantage, because the tire stops lower in the wheel well. The cost is droop past the factory limit. If tire clearance is the goal, a bump stop and limit strap kit gets you there with parts designed to be travel stops.
Will a lift collar improve how my truck handles off-road?
No, and we would rather say so. A collar sets stance and makes room for a taller tire. It does not add wheel travel or change how the suspension absorbs terrain. For that you want a mid travel front kit with bypass shocks and bump stops, or on the Ranger Raptor a rear long travel kit that adds three-plus inches of wheel travel.
Will I need an alignment after installing lift collars?
Any change in ride height changes your alignment numbers, so an alignment check afterward is standard practice regardless of which method you use.
Which lift height should I pick?
Match it to the rake you want gone and the tire you are running, and account for any weight you have added up front. If you are unsure, tell us your truck, your tire size and what you have on the front bumper and we will point you at the right one.
If you take one thing from this page: a lift should change where your truck sits inside its travel, not how far its travel goes. Browse every height and platform in the lift and leveling collar collection, read the full buyer's guide in Lift and Leveling Collars: How They Work and Which One Fits Your Truck, or step up to the mid travel and long travel suspension kits when stance is no longer the thing you are chasing. If you are not sure which applies to your build, call the shop — that conversation is free and it is the part we are best at.